From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D14FC32774 for ; Tue, 23 Aug 2022 08:32:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243645AbiHWIcf (ORCPT ); Tue, 23 Aug 2022 04:32:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344685AbiHWIbf (ORCPT ); Tue, 23 Aug 2022 04:31:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CEF766128; Tue, 23 Aug 2022 01:15:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3F7E461321; Tue, 23 Aug 2022 08:15:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47543C433C1; Tue, 23 Aug 2022 08:15:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661242514; bh=CWO5cFi5S/7DCwalQ4rsgZB2IdcrAI+RfNDTo4EngAY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1BIw3SK5GAXj+jXrVSwOggdpypn9s/J1tNCZssupVYwL2tEo7moYWnKTZxYOTWEyx duILYV6C/rIiVXKHaoMj+IilcymbLmDZCwhA4rVLdOEtWmDDN/lbtTnGkCIysucjwQ uy2z3c7/UH05Tx3YClMe1V2rxAExaRiSNJFH30sk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Mike Snitzer Subject: [PATCH 4.9 056/101] dm raid: fix address sanitizer warning in raid_status Date: Tue, 23 Aug 2022 10:03:29 +0200 Message-Id: <20220823080036.696134505@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080034.579196046@linuxfoundation.org> References: <20220823080034.579196046@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mikulas Patocka commit 1fbeea217d8f297fe0e0956a1516d14ba97d0396 upstream. There is this warning when using a kernel with the address sanitizer and running this testsuite: https://gitlab.com/cki-project/kernel-tests/-/tree/main/storage/swraid/scsi_raid ================================================================== BUG: KASAN: slab-out-of-bounds in raid_status+0x1747/0x2820 [dm_raid] Read of size 4 at addr ffff888079d2c7e8 by task lvcreate/13319 CPU: 0 PID: 13319 Comm: lvcreate Not tainted 5.18.0-0.rc3. #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: dump_stack_lvl+0x6a/0x9c print_address_description.constprop.0+0x1f/0x1e0 print_report.cold+0x55/0x244 kasan_report+0xc9/0x100 raid_status+0x1747/0x2820 [dm_raid] dm_ima_measure_on_table_load+0x4b8/0xca0 [dm_mod] table_load+0x35c/0x630 [dm_mod] ctl_ioctl+0x411/0x630 [dm_mod] dm_ctl_ioctl+0xa/0x10 [dm_mod] __x64_sys_ioctl+0x12a/0x1a0 do_syscall_64+0x5b/0x80 The warning is caused by reading conf->max_nr_stripes in raid_status. The code in raid_status reads mddev->private, casts it to struct r5conf and reads the entry max_nr_stripes. However, if we have different raid type than 4/5/6, mddev->private doesn't point to struct r5conf; it may point to struct r0conf, struct r1conf, struct r10conf or struct mpconf. If we cast a pointer to one of these structs to struct r5conf, we will be reading invalid memory and KASAN warns about it. Fix this bug by reading struct r5conf only if raid type is 4, 5 or 6. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-raid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3173,7 +3173,7 @@ static void raid_status(struct dm_target { struct raid_set *rs = ti->private; struct mddev *mddev = &rs->md; - struct r5conf *conf = mddev->private; + struct r5conf *conf = rs_is_raid456(rs) ? mddev->private : NULL; int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0; bool array_in_sync; unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */